3. 3
Goals
• to exploit the potential of near infrared
spectroscopy
• to demonstrate its capabilities for bio-based
materials characterization
• to highlight the potential of the NIR as a tool
capable of providing complementary
information to other techniques
• to present current trends in NIR developments
4. 4
Bio-materials in construction sector
• In Italy 1 on 12 buildings is made of wood and
growing tendency is observed nowadays
• Bio-based materials are often used for
retrofitting of existing structures, upward
construction or vertical gardens
• Buildings that use bio-materials are not just
sustainable, strong and durable;
they are also beautiful
5. 5
Development priorities
• Structural components
(need for developed wood products -
Engineered Wood Products, high strength wood,
moisture resistant sills, light-weight
beams/joists/studs of bio-composites, sandwich
panels for exterior walls)
• Insulation
(need for compactable bats of cellulose
insulation, environmentally friendly fire
impregnation, high-performance insulation that
provides thinner walls, insulation, optimized for
soundproofing)
• Barrier Materials
(need for bio-based wind and vapor barrier for
moisture-proof exterior walls, waterproofing for
wet areas, façade and roofing materials with
improved durability/serviceability
Source: Per-Erik Eriksson: Future sustainable biobased buildings
9. 9
Why NIR spectroscopy?
No need special sample preparation
Non-destructive testing
Relatively fast measurement
No residues/solvents to waste
Determination of many components simultaneously
High degree of precision and accuracy
Direct measurement with very low cost
Not self standing technology
Overlapping of spectral peaks
Not straightforward interpretation
Needs statistics methods for data analysis
10. 10
chemical industry, microanalysis,
pharmaceutical analysis, soil,
polymers, food and beverages,
surface science, fuels, textile
industry, art conservation,
forensics, PAT, remote sensing
and also wood and paper
industry
NIR applications
11. 11
…but what can we see in wood?
http://www.ifb.ethz.ch/research/sinergia
12. 12
Cellulose (40-50%)
• linear polymer
• long chain
(DP 5000-10000)
• Β-D-Glucopyranose
units
• 1,4-glycosidic bonds
• hydroxyl groups
bonds
• different kind in
wood:
• - amorphous,
- semi-crystalline,
- crystalline
methylene groups
hydroxyl groups
13. 13
Lignin (20-30%)
Softwood (guaiacyl units) Hardwood (guaiacyl + syringyl units)
methoxyl groups
phenolic hydroxyl groups
aldehyde groups
carbonyl groups
18. 18
Use of CA for species classification
Picea abies Pinus cembra Larix sp. Thuja plicata Abies alba Pinus silvestris Tsuga sp.
investigatedsample
19. 19
Wood provenance & NIRS
2163 trees of Norway spruce
from 75 location
in 14 European countries
2163 samples measured
x 5 spectra/sample
= 10815 spectra
20. 20
Differentation of origin
samples form 14 countries (75 locations); totally 10815 spectra was analyzed and evaluated
Austria ▲ Bulgaria ▼ Czech Republic ■ Croatia ■ Estonia Finland France
Germany Hungary Italy Norway Poland Romania Sweden
22. 22
Principal Component Analysis
PCA of spectra of wooden samples coming from six different locations (14 sites) in
Trentino region
Note: second derivative, vector normalization, method: factorization (5 factors)
region: 9590-5250cm-1, 5100-4160cm-1
Strada Alta Valcigolera
Strada Orti Forestali,
Juribello
Paneveggio
Cadino 06
Cadino 43
Cadino 49
Folgaria 04
Folgaria 22
Monte Sover 7
Monte Sover 11
Monte Sover 14
Monte Sover 69
Caoria Valsorda
23. 23
Cluster Analysis
CADINO CADINO CADINO
CA – wooden samples from 3 different districts of Cadino valley
Note: second derivative, vector normalization, Ward’s algorithm, region: 7089-5072cm-1
25. Particleboards characterization
25
A
B
C
Raw resources: Eastern redcedar (Juniperus virginiana L.)
Single- and three-layers panels
manufactured from raw material using 9% urea formaldehyde, combination of 15%
modified corn starch and 2% urea formaldehyde adhesive
12345678910111213141516171819
-0,008
0
0,008
40004500500055006000650070007500
wavenumber (cm-1)
PC2,PC3
PC2
PC3
26. 26
Selection of biomass
for optimal bio-conversion process
PCA of willow clones. Note: pre-processing:
2nd derivative + vector normalization,
17 smoothing points, region: 6869-5847 cm-1,
method: factorization, 3 factors
duotur
sprint
turbo
wodtur
monoturstart
oltur
tur PC3
PC4
PC2
27. 27
Willows utilization
willows
thermo-chemical
conversion
chemical
conversion
mechanical-chemical
conversion
combustion pyrolysis gasification fermentation
anaerobic
digestion
estrificationpulping
panel
production
heat syngas pulp&paper fiber-panel ethanol biogas biodieselcharcoalsyngasbio-oil
high lignin content high carbohydrate content
high fiber
content
extraction
high extractives content acumulation of heavy metalsfast
resprouting
manufacturing environmental
engineering
phytominig
phyto-
remediation
biofiltrationfurniturebasketry
metalsclean soilclean waterchairscontainers
cosmetic foodpharmaceutic
cream
anti-
phlogistic
anti-
pyretic preservative
anti-
oxidantshampoo
cultivation
apiculture
honeypollination
construction
green
architecture
fencesroadmats
fast growingearly flowering
33. 33
Wood thermal treatment
fir spruce larch
parameter ML EMC ML EMC ML EMC
range (cm-1) 7502-6098
5450-4246
6102-4246 10996-10098
9303-8501
5018-4435
8505-4435 9403-5446 9403-7498
6102-5446
pre-processing 1der +MSC 1 der + VN VN 1 der + VN 1 der + VN 1 der +MSC
r2 98.67 97.58 98.48 98.83 97.88 97.69
RMSECV 0.26 0.25 0.25 0.17 0.39 0.19
RPD 8.66 6.42 8.11 9.42 6.87 6.58
rank 3 3 3 4 4 5
Termovuoto: open system:
(volatile products of the process are
continuously removed from the kiln by
means of a vacuum pump)
The treatment time: 3 hours
Pressure: 0.2 bar
treatment temperatures of 160, 180,
200 and 220ºC.
+
5hardwoods…
195 samples measured x 5 spectra/sample = 975 spectra
34. 34
New spectra presentation
Wild cherry
(Prunus avium)
no treated 160ºC 180ºC 200ºC 220ºC
-1,25
-1
-0,75
-0,5
-0,25
0
am. cell OH
cell CH CH2
cell CH2
cell CO OH CH2
cell OH
cell OH CH CH2
cell OH CO
cryst. cell OH
cryst. cell CH
cryst. cell OH CH
cell hemi CH
cell hemi CH CH2 OH CO
cell hemi OH CH
cell hemi lig CH
extr. CH
hemi C=O
hemi CH
hemi CH
hemi OH
hemi CH
hemi lig extr. CH C=C C=O
lig CH
lig CH
lig CH
lig
lig OH
H2O
H2O
xylograms
35. 35
Xylograms; different species
-1,25
-1
-0,75
-0,5
-0,25
0
am. cell OH
cell CH CH2
cell CH2
cell CO OH CH2
cell OH
cell OH CH CH2
cell OH CO
cryst. cell OH
cryst. cell CH
cryst. cell OH CH
cell hemi CH
cell hemi CH CH2 OH CO
cell hemi OH CH
cell hemi lig CH
extr. CH
hemi C=O
hemi CH
hemi CH
hemi OH
hemi CH
hemi lig extr. CH C=C C=O
lig CH
lig CH
lig CH
lig
lig OH
H2O
H2O
-1,25
-1
-0,75
-0,5
-0,25
0
am. cell OH
cell CH CH2
cell CH2
cell CO OH CH2
cell OH
cell OH CH CH2
cell OH CO
cryst. cell OH
cryst. cell CH
cryst. cell OH CH
cell hemi CH
cell hemi CH CH2 OH CO
cell hemi OH CH
cell hemi lig CH
extr. CH
hemi C=O
hemi CH
hemi CH
hemi OH
hemi CH
hemi lig extr. CH C=C C=O
lig CH
lig CH
lig CH
lig
lig OH
H2O
H2O
-1,25
-1
-0,75
-0,5
-0,25
0
am. cell OH
cell CH CH2
cell CH2
cell CO OH CH2
cell OH
cell OH CH CH2
cell OH CO
cryst. cell OH
cryst. cell CH
cryst. cell OH CH
cell hemi CH
cell hemi CH CH2 OH CO
cell hemi OH CH
cell hemi lig CH
extr. CH
hemi C=O
hemi CH
hemi CH
hemi OH
hemi CH
hemi lig extr. CH C=C C=O
lig CH
lig CH
lig CH
lig
lig OH
H2O
H2O
-1,25
-1
-0,75
-0,5
-0,25
0
am. cell OH
cell CH CH2
cell CH2
cell CO OH CH2
cell OH
cell OH CH CH2
cell OH CO
cryst. cell OH
cryst. cell CH
cryst. cell OH CH
cell hemi CH
cell hemi CH CH2 OH CO
cell hemi OH CH
cell hemi lig CH
extr. CH
hemi C=O
hemi CH
hemi CH
hemi OH
hemi CH
hemi lig extr. CH C=C C=O
lig CH
lig CH
lig CH
lig
lig OH
H2O
H2O
Black locust
(Robinia pseudoacacia)
no treated 160ºC 180ºC 200ºC 220ºC
Norway spruce
(Picea abies)
no treated 160ºC 180ºC 200ºC 220ºC
Silver fir
(Abies alba)
no treated 160ºC 180ºC 200ºC 220ºC
European larch
(Larix decidua)
no treated 160ºC 180ºC 200ºC 220ºC
Wild cherry
(Prunus avium)
no treated 160ºC 180ºC 200ºC 220ºC
European beech
(Fagus silvatica)
no treated 160ºC 180ºC 200ºC 220ºC
European ash
(Fraxinus excelsior)
no treated 160ºC 180ºC 200ºC 220ºC
-1,25
-1
-0,75
-0,5
-0,25
0
am. cell OH
cell CH CH2
cell CH2
cell CO OH CH2
cell OH
cell OH CH CH2
cell OH CO
cryst. cell OH
cryst. cell CH
cryst. cell OH CH
cell hemi CH
cell hemi CH CH2 OH CO
cell hemi OH CH
cell hemi lig CH
extr. CH
hemi C=O
hemi CH
hemi CH
hemi OH
hemi CH
hemi lig extr. CH C=C C=O
lig CH
lig CH
lig CH
lig
lig OH
H2O
H2O
-1,25
-1
-0,75
-0,5
-0,25
0
am. cell OH
cell CH CH2
cell CH2
cell CO OH CH2
cell OH
cell OH CH CH2
cell OH CO
cryst. cell OH
cryst. cell CH
cryst. cell OH CH
cell hemi CH
cell hemi CH CH2 OH CO
cell hemi OH CH
cell hemi lig CH
extr. CH
hemi C=O
hemi CH
hemi CH
hemi OH
hemi CH
hemi lig extr. CH C=C C=O
lig CH
lig CH
lig CH
lig
lig OH
H2O
H2O
-1,25
-1
-0,75
-0,5
-0,25
0
am. cell OH
cell CH CH2
cell CH2
cell CO OH CH2
cell OH
cell OH CH CH2
cell OH CO
cryst. cell OH
cryst. cell CH
cryst. cell OH CH
cell hemi CH
cell hemi CH CH2 OH CO
cell hemi OH CH
cell hemi lig CH
extr. CH
hemi C=O
hemi CH
hemi CH
hemi OH
hemi CH
hemi lig extr. CH C=C C=O
lig CH
lig CH
lig CH
lig
lig OH
H2O
H2O
-1,25
-1
-0,75
-0,5
-0,25
0
am. cell OH
cell CH CH2
cell CH2
cell CO OH CH2
cell OH
cell OH CH CH2
cell OH CO
cryst. cell OH
cryst. cell CH
cryst. cell OH CH
cell hemi CH
cell hemi CH CH2 OH CO
cell hemi OH CH
cell hemi lig CH
extr. CH
hemi C=O
hemi CH
hemi CH
hemi OH
hemi CH
hemi lig extr. CH C=C C=O
lig CH
lig CH
lig CH
lig
lig OH
H2O
H2O
Sessile oak
(Quercus peraea)
no treated 160ºC 180ºC 200ºC 220ºC
36. 36
PLS models for TM softwoods
y = 0.9522x - 0.1186
R
2
= 0.944
-10
-8
-6
-4
-2
0
2
-10 -8 -6 -4 -2 0 2
reference
estimated
y = 0.9782x + 0.218
R
2
= 0.9662
6
7
8
9
10
11
12
13
6 7 8 9 10 11 12 13
reference
estimated
Mass loss Equilibrium Moisture Content
38. 38
Wood sterilization
How to detect if the wood was appropriately
thermally treated?
• standard ISPM No15;
• Temperature: 56°C in the core of wood
• Treatment time: 30minutes
39. 39
ISPM-15
Low temperature thermal treatment of wood
35
40
45
50
55
60
65
70
75
80
85
90
95
100
105
35 40 45 50 55 60 65 70 75 80 85 90 95 100 105
treatment temperature, degC
predictedtemperature,degC
calibration
validation
• to investigate an effect of the temperature on
wood samples of different wood species:
• Spruce (softwood with resin)
• Fir (softwood without resin)
• Poplar (hardwood)
• different treatment times:
• 0.5 hours (30 minutes)
• 1 hour
• 3 hours
• 6 hours
• different treatment temperatures:
• 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95,
100°C
• three samples for repetition/statistics
• five-times spectra measurements for analysis
of weathering effect:
• Conditioned after treatment
• Measured after 1month
• Measured after 3 months
• Measured after 6 mounts
• Measured after 12 mounts
468 samples measured x 5 spectra/sample x 5 repetition/sample = 9360 spectra
40. 40
NIR-based method for verification of the
ISPM-15 treatment*
changestothespectrachangestothespectra
NO TREATED
TREATED
Spectra
+
model
63. 63
Calibration transfer
y = 0.93x + 1.86
R² = 0.93
25,0
27,0
29,0
31,0
33,0
25,0 27,0 29,0 31,0 33,0
Measured total lignin content (%)
NIR‐predicted total lignin content (%)
y = 0.93x + 1.86
R² = 0.93
y = 0,99x + 0,31
R
2
= 0,86
25,0
27,0
29,0
31,0
33,0
25,0 27,0 29,0 31,0 33,0
Measured total lignin content (%)
NIR‐predicted total lignin content (%)
measurement of samples with
equipment #1
measurement of selected
samples with equipment #2equipment #2 model
development based on samples
measured with instrument #1
model #1 development
calculation of transfer
matrix
selection of
calibration samples
by Kennard Stone
algorithm
64. 64
Conclussions
NIR technique has been successfully used for:
• species and provenance recognition
• estimation chemical composition, physical and mechanical
properties
• monitoring chemical changes in wood during thermal modification,
weathering, waterlogging and decay
• recognition and classification of coatings
• characterization of archeological wood and cultural heritage objects
• service life prediction of wooden elements and structures
• paper characterization
• in-field applications
Current developments in the fields of optics and electronics open
new application for NIR. Its non-destructive character and simple
measurements allows assisting experts in the estimation of
material properties in a fast and repeatable way